On 6/29/24 13:14, John Levine wrote:
That's a big part of it. The IPv4 address space is small enough that mail systems can keep a separate reputation for every IP address and use that as part of the filtering rules. With v6 that's obviously impossible, particularly since it's not hard to hop to a new address for every message.
Okay but there are other efficient ways of searching for a source
address besides array lookup. Routers have to do similar lookups
on destination addresses all the time, and they manage.
Keith
